ADR danger labels: every model explained
Colour, symbol and number: how to recognise each class on a package and on the vehicle.
In this guide
Drums, jerrycans and boxes of dangerous goods carry a coloured diamond: the danger label. Its colour, symbol and number tell you the class and the hazard without reading a word. On the vehicle the same design appears in a larger size, as a placard. Both come up in a lot of ADR exam questions.
How a danger label is laid out
A danger label is a square set at 45°, a diamond, measuring at least 100 × 100 mm. A line runs about 5 mm inside the edge. In the upper half it is the colour of the symbol, in the lower half the colour of the number (ADR 5.2.2.2.1.1.2). Gas cylinders may have smaller labels sized for the cylinder shoulder (ADR 5.2.2.2.1.2).
- Upper half: the symbol, such as a flame, a skull and crossbones or a gas cylinder.
- Bottom corner: the class number. Classes 4.1, 4.2 and 4.3 show just a 4, and 6.1 and 6.2 just a 6. Labels 5.1 and 5.2, on the other hand, show the full number (ADR 5.2.2.2.1.3).
- Class 1: the division and the compatibility group letter go above the 1, for example 1.1D. Divisions 1.4, 1.5 and 1.6 show the division number in the upper half instead of the bomb (ADR 5.2.2.2.1.4).
Symbols, text and numbers are black. There are exceptions: on the class 8 label the number and text are white, on labels with an entirely red, green or blue background they may be white, and the flame on the 5.2 label may be white (ADR 5.2.2.2.1.6).
Every label model at a glance
The label models are set out in ADR 5.2.2.2.2. Learn them by background and symbol.
| Model | Symbol and background |
|---|---|
| 1 | exploding bomb (divisions 1.1 to 1.3) background: orange |
| 1.4, 1.5, 1.6 | division number instead of a symbol background: orange |
| 2.1 | flame background: red |
| 2.2 | gas cylinder background: green |
| 2.3 | skull and crossbones background: white |
| 3 | flame background: red |
| 4.1 | flame background: white with seven vertical red stripes |
| 4.2 | flame background: upper half white, lower half red |
| 4.3 | flame background: blue |
| 5.1 | flame over circle background: yellow |
| 5.2 | flame background: upper half red, lower half yellow |
| 6.1 | skull and crossbones background: white |
| 6.2 | three crescents superimposed on a circle background: white |
| 7A | trefoil, the word RADIOACTIVE with one red bar background: white |
| 7B, 7C | trefoil, two or three red bars background: upper half yellow, lower half white |
| 8 | liquids spilling from two glass vessels and attacking a hand and a metal background: upper half white, lower half black number 8 in white |
| 9 | seven vertical black stripes in the upper half background: white number 9 underlined |
| 9A | stripes on top, below them a group of batteries, one broken and emitting flame background: white number 9 underlined |
For Class 7 the label depends on the category: 7A for I-WHITE, 7B for II-YELLOW and 7C for III-YELLOW. Fissile material also gets label 7E (ADR 5.2.2.1.11.1).
Common mix-ups in the exam
- 2.3 or 6.1: both show a skull and crossbones on white. The number decides: 2 means a toxic gas, 6 a toxic substance.
- 2.1 or 3: both are red with a flame. A 2 means a gas, a 3 a liquid.
- 4.1, 4.2 and 4.3: all have a flame and a 4 at the bottom. You tell them apart by the background: red stripes, white over red, or blue.
- 5.1 or 5.2: 5.1 is all yellow, with a flame over a circle. 5.2 is red at the top and yellow at the bottom. The 5.2 label already indicates that the product may be flammable, so a label 3 isn’t needed (ADR 5.2.2.1.9).
Where the labels go on a package
The labels a substance needs are listed in Chapter 3.2, Table A, column (5). A special provision in column (6) can change that (ADR 5.2.2.1.1). If column (5) lists several models, all of them go on the package. Methanol (UN 1230) is Class 3 but carries labels 3 and 6.1, because it is also toxic.
These rules apply when fixing them (ADR 5.2.2.1.6):
- all labels on the same surface, if the package is big enough,
- for Classes 1 and 7, near the proper shipping name,
- nothing may cover or obscure them, whether part of the packaging or another label or mark,
- several labels next to each other.
A package that is too small or an awkward shape can have the label attached securely with a tag. IBCs of more than 450 litres capacity and large packagings are labelled on two opposite sides (ADR 5.2.2.1.7). The same goes for packages of radioactive material (ADR 5.2.2.1.11.1).
Placards on the vehicle
Vehicles, containers and tanks carry the same models as placards. A placard is at least 250 × 250 mm, the line runs 12.5 mm from the edge, and the class number is at least 25 mm high (ADR 5.3.1.7.1). Where the placards go depends on the load:
- Tank vehicles and bulk loads: on both sides and at the rear (ADR 5.3.1.4.1).
- Containers and tank-containers: on both sides and at each end. If they can’t be seen from outside, the vehicle gets them on both sides and the rear too (ADR 5.3.1.2 and 5.3.1.3).
- Packages only: placards are needed only for Class 1 (except 1.4S) and Class 7 (except excepted packages), on both sides and at the rear (ADR 5.3.1.5). A lorry carrying jerrycans of petrol therefore doesn’t need a placard.
- Empty and uncleaned: tank vehicles and tanks that haven’t been cleaned or degassed keep the placards of the last load (ADR 5.3.1.6.1).
- Class 7: here the placard is model 7D (ADR 5.3.1.1.3).
If a load stays within the 1,000 points rule, Chapter 5.3 doesn’t apply at all. Placards and orange plates are then not needed, but the labels on the packages still are.
The environmentally hazardous substance mark
Next to the danger labels you’ll often see a white diamond with a black fish and tree. That isn’t a danger label but a mark, which is why it has no class number. It measures at least 100 × 100 mm (ADR 5.2.1.8.3).
Packages containing substances that meet the criteria in 2.2.9.1.10 must carry it. Single packagings and inner packagings holding no more than 5 litres of liquid or 5 kg of solid are exempt (ADR 5.2.1.8.1). On vehicles and containers a mark of at least 250 × 250 mm is added whenever placards are required there (ADR 5.3.6).
Three everyday examples
UN 1203 MOTOR SPIRIT or GASOLINE or PETROL. Column (5) shows 3. Every jerrycan therefore gets the red label 3. A tank vehicle carries the same model as a placard on both sides and at the rear, plus orange plates showing 33 and 1203. You can read how to decode them in our guide to orange plates.
UN 1072 OXYGEN, COMPRESSED. Column (5) shows 2.2 and 5.1. The cylinder carries the green gas label with the yellow 5.1 label next to it, because oxygen is also oxidizing.
UN 3480 LITHIUM ION BATTERIES. The package gets label 9A. If the batteries travel in a container, the container carries placard 9, never 9A (ADR 5.3.1.1.4).
Put it into practice
Learn the background colours first, then the symbols. Our guide to the dangerous goods classes explains what each class covers.
In the free test you get an explanation and the ADR reference after every answer. In the app you can also mark up a vehicle yourself with plates and placards.
Sources
ADR 2025: Chapter 3.2, Table A (columns 5 and 6), sub-section 5.2.1.8, section 5.2.2 with the models in 5.2.2.2.2, and sections 5.3.1 and 5.3.6. In Great Britain, ADR applies through the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2009. This guide explains the basics. When you label an actual consignment, the wording of ADR is what counts.
Updated: 2 October 2026